The present invention relates to a device for producing non-abrasive coke forms from brown-coal briquets, according to which the briquets are preheated, dehydrated, carbonized and subsequently cooled, with the entire operation being effected in at least three stages and with the use of hot gas circuits in which the hot gas is composed substantially of the burnt lean gas of the carbonization or low temperature carbonization process.
Such devices are well known in the art. Frequently the individual stages are united or merge into one another. While a complete separation of the individual stages is technically very difficult to achieve, in view of a better utilization of the circulating hot gases, a complete separation of the hot gas circuits would be desirable. The technology also seeks to increase the mechanical resistance of the produced coke forms. Particular difficulties result from the fact that, in their circulation, the hot gases carry along large quantities of coal dust originating in the abrasion of the briquets and, at the same time, contain oil and tar components. This entails particular problems of condensation which, up to date, have not been solved in the art in a satisfactory manner. In this respect again, an increased mechanical resistance of the briquets to be coked is desirable.
The condensation and scrubbing of oil and tar components out from the dust-laden gases leads to the necessity of removing the washing liquids, which are loaded with coal dust, from the scrubbing circuit, since their viscosity becomes excessive and then can no longer be pumped. The further processing of such mixtures is expensive wherefore a better dust separation from the circulating gases would represent a technological progress, all the more as the dust entrained by the circulating gases causes clogging in almost all parts of the equipment, and which can be cleared only by troublesome manual work.
In known devices, temperatures of 110.degree. to 135.degree. C for the preheating, 230.degree. to 330.degree. C for the drying and 550.degree. to 650.degree. C for the coking are used.
It is also known to use the lean gas, produced during the carbonization, for preheating and drying and as the drying gas for preheating and subsequently, to evacuate the gases into the free atmosphere. It is also known to separate the individual stages by means of mechanical members, such as lids. However, this measure frequently entails disturbances in the plant.